craiso

I have been studying some of the information found on http://gojeep.willyshotrod.com/index.htm. In the alignment section, he talks about measuring the caster angle from the bolt heads on the differential cover. According to the reading, a stock Jeep should measure at 87.5* or 2.5*. Please bear with me; if the cover is perpendicular to a level floor (90*), then would the bottom of the cover be tilted towards the front of the Jeep, or the rear to get the 2.5*? I know you can make the measurements from the upper ball joint, but my Jeep is so low that I can't get a good measurement.

4.3L XJ

Having done this, that is not a good way to do it. All that tells you is the pinion angle. Modern Dana front ends generally have different pinion than castor angles. The way to do it is to remove the wheel and measure the angle of the top of the upper ball joint. You can get free apps for a smart phone and use it

firebane

Angle finder on top or bottom of C
Should read between 5-7 degrees

Unless your lifted or been in an accident shouldn't need to worry about caster.

dave1123

Caster angle must be measured with the axle loaded, as in wheels on the ground or at normal height on jackstands. You should use a square on the floor against the upper ball joint, then measure from the square to the center of both ball joints. Subtract the upper and lower measurement gives you the distance between a true perpendicular line. If you measure the vertical distance between the ball joints, then use trigonometry you can compute the angle. Factory says 7* +or- 0.5* is correct. If I remember correctly, the SIN of the angle is the actual distance in 5". It's been 10 years since I used trig.